Apple has revoked Monster’s MFi license in wake of its Beats lawsuit, reports The Wall Street Journal. Monster, the A/V company who manufactured headphones for Beats in its early days, filed a lawsuit against the company in January for duping it out of potential proceeds from the Apple acquisition.

Monster’s general counsel David Tognotti said Apple’s move to pull its MFi license is in retribution for the suit, and that it can significantly disrupt their business—which still involves building premium headphones. “It shows a side of Apple that consumers don’t see very often,” he said. “Apple can be a bully.”

Mr. Tognetti adds that Monster and Apple have worked well for years, with it paying the iPhone maker more than $12 million in licensing fees. Close to 1,000 of Monster’s 4,000+ product log were made through the MFi program. Apple told Tognetti their relationship was no longer “mutually beneficial.”

Short for “Made for iPhone/iPod/iPad,” Apple’s MFi program gives third-party manufacturers components, technical support and a certification logo to ensure their products will work with iOS devices. In recent years, consumers have learned to look for the logo when buying accessories as a sign of quality.

As a result of losing its MFi license, Monster has been forced to change its packaging, redesign some of its products, and it has even had to stop manufacturing current products to avoid using licensed technology. Its lawsuit against Beats is currently pending in Los Angeles County Superior Court, in California.